Converted the skill database to YAML (#4531)

* Combines skill_cast_db, skill_castnodex_db, skill_copyable_db, skill_nonearnpc_db, skill_require_db, and skill_unit_db into skill_db.
* Introduces a cached YAML class for quicker lookups.
* General cleanups and optimizations.
* Includes CSV2YAML conversion tool.
Thanks to @Lemongrass3110!
Co-authored-by: Lemongrass3110 <lemongrass@kstp.at>

src/common/database.cpp

@@ -125,9 +125,15 @@ bool YamlDatabase::load(const std::string& path) {
 
 	this->parseImports( rootNode );
 
+	this->loadingFinished();
+
 	return true;
 }
 
+void YamlDatabase::loadingFinished(){
+	// Does nothing by default, just for hooking
+}
+
 void YamlDatabase::parse( const YAML::Node& rootNode ){
 	uint64 count = 0;